The present invention relates to the technical field concerned with machines for packaging articles, e.g. opto-magnetic supports, like compact discs, CD ROM, DVD, etc. into relative book-like containers.
More precisely, the invention relates to a method for introducing a cover sheet between a transparent film and a book-like container, wrapped within the film, and to a device which carries out the method.
As far as CDs and DVDs packaging, those skilled in the art currently know containers made of plastic material and formed by a pair of planar closure members, substantially book-like hinged to each other along a common edge and equipped with suitable closing means, e.g. snap means situated on the side opposite to the joining edge.
The closure members are designed in a way to form a base closure member, including suitable means fixed to its inner surface for receiving the articles (a CD and/or a DVD) and possibly informative leaflets, and an upper closure member designed to close the container with the cooperation of the above mentioned closing means.
The closure members are wrapped externally by a transparent protective film, fastened to the closure members along the edges opposite to the hinge side.
Usually, a cover sheet carrying information about the article packaged in the container, is introduced between the transparent film and the outer surface of the container.
These packages are currently processed by known automatic machines which take closed containers one by one from a suitable magazine, open them and introduce CDs or DVDs therein together with an accompanying informative leaflet, also taken one by one from respective magazines.
Introducing a cover sheet between the transparent film and the container is a particularly difficult and complicated operation step of the packaging process, because of the close contact between the film and the container.
A serious problem which often occurs during the introduction of the cover sheet derives from the fact that the containers are fed, after being opened, with their inner part turned upwards, so as to introduce therein the articles (CDs or DVDs) and informative leaflets.
British document GB-A-2.246.549 describes a method for opening containers for video cassettes (VHS) and for introducing an informative leaflet in the area defined between the outer walls of the container and a transparent film wrapping the container, and the corresponding apparatus which carries out the method.
In particular, the above mentioned apparatus, working on open containers in flat configuration and turned upwards, includes means for moving downwards the transparent film, away from the outer walls of the container, thus opening the walls forming the container by an angle wide more than 180xc2x0.
Suitable working means introduce the informative leaflet, folded and/or undulated, into the area defined between the inclined walls of the container and the transparent film.
The introducing means grip the informative leaflet, push it into the area between the opened members and the transparent film detached therefrom, and then release it, after the introduction has been completed.
Afterwards, the closure members of the container are rotated until they reach again the flat configuration, thus making the informative leaflet to stretch coplanar and substantially touching the outer surfaces of the container.
One of the disadvantages of the above apparatus derives from the fact that the cover sheet can be placed incorrectly, which has a negative effect on the container aesthetic look and can reduce the acceptance of the final client.
In any case, a very serious problem is always present, which problems derives from possible stumbling of the cover sheet while being inserted into the area between the outer surfaces of the opened members of the container and the transparent film, as the sheet is pushed into the above area by relative means.
The object of the present invention is to propose a method for introducing a cover sheet between a transparent film and book-like openable container, which avoids the above mentioned disadvantages and allows to introduce the cover sheet correctly and automatically, in a simple and easy way, while ensuring a faultless positioning of the same cover sheet.
Another object of the present invention is to propose a devices which carries out the proposed method and can easily be adapted to different sizes of the containers, so as not to hinder the introduction of the cover sheet.
A further object of the present invention is to propose a method and a related device, which introduce the cover sheet into a continuously moving container.
A still further object of the present invention is to propose a device obtained by a simple technical solution which ensures high reliability and production rate in any operation condition, and which ensures rapid and best introduction of the cover sheet between the transparent film and the container.
The above mentioned objects are obtained according to the invention, by the proposed method for introducing a cover sheet between a transparent protective film and a book-like container wrapped within the film, said container 4 being substantially formed by a couple of closure members 4a, 4b, which are hinged one to the other along a corresponding edge 4c and which are wrapped within said protective film 3, fastened to said closure members 4a, 4b along the edges opposite to the hinge edge 4c, said method being characterized in that it includes:
opening the container 4 by opening said closure members 4a, 4b by an angle wider than 180xc2x0 with respect to the closing configuration of the closure members 4a, 4b; 
detaching said transparent film 3 from the outer surface of said closure members 4a, 4b; 
making a transversal corrugation in a cover sheet 2, situated beside said opened container 4, near an area Z defined by said opened closure members 4a, 4b and said detached film 3;
introducing of gripping means 10, situated on the side opposite with respect to the corrugated cover sheet 2, into said area Z;
gripping the above mentioned corrugated cover sheet 2 and pulling it, by said gripping means 10, into said area Z;
releasing of the above cover sheet 2 inside said area Z, which cover sheet consequently spread across said area Z;
defining a flattened configuration of the closure members 4a, 4b so that said cover sheet 2 spreads over a plane.
The proposed method is carried out in accordance with the above mentioned objects and according to the invention, by a device for introducing a cover sheet between a transparent protective film and a book-like container wrapped externally within the film, with said container 4 being substantially formed by a couple of closure members 4a, 4b, which are hinged to each other along a corresponding edge 4c and which are externally wrapped with said protective film 3, fastened to said closure members 4a, 4b along the edges opposite to the hinge edge 4c, said device characterized in that it includes: means 20 for opening the container 4, moved by first conveying means 31, which opening means support and open said closure members 4a, 4b by an angle wider than 180xc2x0 with respect to the close configuration of said members 4a, 4b; first means for detaching said transparent film 3 from the outer surface of said open container 4; second means 40, operated in time relation with said first means, for corrugating crosswise a cover sheet 2 situated beside said open container 4, near an area Z delimited by said closure members 4a, 4b and said detached film 3; gripping means 10, situated on the side opposite to said corrugated cover sheet 2 and moved by second conveying means 32 for entering said area Z and removably gripping said cover sheet 2 and pull it completely into said area Z.